function $visible(url){
	var res=false;
	v=new Ajax.Request(url, {
	  method: 'get',
	  asynchronous : false,
	  onSuccess: function(transport) {
	    res=true;
	  },
	  onFailure: function(transport) {
	  	res=false;
	  }
	});
	return res;
}
function ajax_content(url,method,param){
	var res="";
	if(method==null) method='post';
	v=new Ajax.Request(url, {
	  method: method,
	  parameters : param,
	  asynchronous : false,
	  onSuccess: function(transport) {
	    res=transport.responseText;
	  },
	  onFailure: function(transport) {
	  	res="";
	  }
	});
	return res;
}